Scout Willis is the latest celeb to hop on the waist training bandwagon!

Demi Moore and Bruce Willis' 23-year-old daughter accentuated her narrow waist with the help of the trendy apparatus Wednesday during a hike in Runyon Canyon with sister Tallulah Willis. Scout's waist trainer looked cinched up good and tight, but omitted a key part of this fitness phenomenon: The obligatory selfiehealthy to show off those hourglass curves!

Pretty much. Pouya Shafipour, M.D., of Wellesley Medical in L.A. told E! News that while waist training "is not so much about medical results," he thinks it "makes you feel more confident. It makes you want to exercise more."

Nobody go too crazy with the corsets, though, OK? Dr. Paul Nassif of E!'s Botched series warns of possible internal organ damage these suckers might do. He noted that while waist trainees "will visibly streamline the appearance of the body," the device will "not have any permanent slimming effects."

Sounds like Scout's got the right idea getting her fitness on in nature. Selfies, sadly, do not burn many calories.